WO2022127431A1

WO2022127431A1 - Differential-pressure antigravity filling and solidifying device under action of external field and process method

Info

Publication number: WO2022127431A1
Application number: PCT/CN2021/128992
Authority: WO
Inventors: 管仁国; 付莹; 姜巨福; 陈强
Original assignee: 大连交通大学
Priority date: 2020-12-18
Filing date: 2021-11-05
Publication date: 2022-06-23

Abstract

Provided are a differential-pressure antigravity filling and solidifying device under the action of an external field and a process method. The device comprises a solidifying cavity, a high-pressure portion, a low-pressure portion and a vacuum portion, wherein the solidifying cavity comprises an upper cavity and a lower cavity; a casting mould is arranged in the upper cavity; the upper cavity and the lower cavity are connected by means of an intermediate plate; a liquid delivery pipe is arranged between the upper cavity and the lower cavity and passes through the center of the intermediate plate; a hydraulic lifting platform is arranged at a lower end of the lower cavity, and a smelting crucible is arranged at an upper end of the hydraulic lifting platform; an induction smelting device is arranged at the bottom of the lower cavity; an electromagnetic stirring device is arranged at an upper end of the induction smelting device; and the lower cavity is provided with an induced electricity inlet in a position corresponding to the electromagnetic stirring device and the induction smelting device. The present invention mainly utilizes a vacuum and electromagnetic-coupling external field processing device and a differential-pressure anti-gravity filling and solidifying method therefor, and applies an electromagnetic field and a vacuum field to a melt, thus achieving the effects of effectively removing gases in the melt, promoting the floating of inclusions, and obtaining a uniform fine casting structure.

Description

A kind of differential pressure anti-gravity filling solidification device and process method under the action of external field

technical field

The invention relates to the technical field of low-pressure casting, in particular, to a differential pressure anti-gravity mold filling and solidification device and a process method under the action of an external field.

Background technique

Low pressure casting technology is a casting technology between pressure casting and gravity casting, mainly used in low pressure casting of non-ferrous metals. The technology has the advantages of high raw material utilization, less casting defects, less oxide inclusions, high dimensional accuracy, and easy adjustment of the casting speed. However, the casting obtained by the low pressure casting method has poor uniformity of solidification structure and coarse grains, which seriously reduces the performance of the casting.

Grain refinement treatment is an important method to improve the performance of castings. For the most widely used aluminum alloy castings, Al-Ti alloy or Al-Ti-B alloy grain refiners are generally used in the industry, which can reduce the hot cracking and segregation tendency of the castings while refining the grains and reduce the porosity. Rate. The existing process is characterized by adding Al-Sr intermediate alloy, mixed rare earth (Re) and Al-Zr intermediate alloy to the aluminum alloy melt in the tundish for modification and refinement treatment to improve product quality. However, because the refiner is extremely sensitive to factors such as melt temperature, treatment time, and addition method, the refining effect is quite different, and the addition of alloying elements increases the production cost, changes the alloy composition, and affects the recycling of the alloy. On the other hand, stirring the melt is a method to improve the performance of castings; the traditional mechanical stirring process is simple, but because the stirrer is in direct contact with the melt, it is easy to contaminate the melt under the action of friction stirring for a long time; the existing The electromagnetic stirring method uses a steady and constant magnetic field to increase the subcooling degree of the metal melt, thereby increasing the nucleation rate and refining the solidification structure, but the strong magnetic field equipment is expensive and complicated, the pouring process requires high temperature control, and the steady and constant magnetic field cannot remove the molten metal. Gases and inclusions in the body.

Therefore, it is necessary to design a differential pressure anti-gravity filling and solidification device and a process method under the action of an external field.

SUMMARY OF THE INVENTION

According to the above, the existing low-pressure casting technology has the technical problems that impurities and gas cannot be completely removed and cannot be completely stirred, and a differential pressure anti-gravity filling and solidification device and process method under the action of an external field are provided. The invention mainly utilizes the vacuum and electromagnetic coupling external field processing device and the differential pressure anti-gravity filling and solidification method, by applying electromagnetic field and vacuum field to the melt, so as to effectively remove the gas in the melt, promote the floating of inclusions, and obtain The effect of uniform and fine casting structure.

The technical means adopted in the present invention are as follows:

A differential pressure anti-gravity filling and solidification device under the action of an external field is characterized in that it comprises: a solidification cavity, a high pressure part, a low pressure part and a vacuum part, the solidification cavity comprises: an upper cavity and a lower cavity, the The upper cavity is provided with a casting mold, the upper cavity and the lower cavity are connected by an intermediate plate, and an infusion tube is arranged between the upper cavity and the lower cavity, and the infusion tube passes through the intermediate plate The lower end of the lower cavity is provided with a hydraulic lifting platform, the upper end of the hydraulic lifting platform is provided with a melting crucible, the bottom of the lower cavity is provided with an induction melting device, and the upper end of the induction melting device is provided with an electromagnetic a stirring device, the lower cavity is provided with an induction electric inlet at the corresponding position of the electromagnetic stirring device and the induction melting device; the high pressure part includes a constant pressure high pressure tank and a valved air duct, the constant pressure high pressure tank The lower ends of the upper cavity and the lower cavity are connected through the valved air conduit; the low pressure part includes a constant pressure low pressure tank and a valved air conduit, and the constant pressure low pressure tank passes through the valved conduit. The air pipe is connected to the upper cavity; the vacuum part includes a vacuum pump, a vacuum tank and a valved air pipe, the vacuum pump is connected to the vacuum tank, and the vacuum tank is connected to the valve through the valved air pipe The lower end of the upper cavity and the upper end of the lower cavity.

Further, the material of the water cooling jacket of the electromagnetic stirring device is austenitic stainless steel; the upper end of the lower cavity is provided with a quartz glass observation hole.

Further, inside the constant pressure high pressure tank is high pressure argon gas; inside the constant pressure low pressure tank is low pressure argon gas.

The present invention also provides a solidification process of a differential pressure anti-gravity filling solidification device under the action of an external field, characterized in that the solidification process steps include:

Step S1: put the aluminum alloy raw material or the intermediate alloy of pure aluminum and related elements into the smelting crucible after drying and removing surface impurities, start the induction melting device to melt the raw material into liquid, and then use the hydraulic lifting platform to melt the raw material into a liquid. The smelting crucible is lifted up, metamorphic agent is used for metamorphism, and high-purity argon gas with a purity greater than 99.99% is used for degassing, and then slag removal is carried out;

Step S2: After slag removal, use the hydraulic lifting platform to lower the melting crucible to the induction melting device, close the middle plate, install the infusion pipe, the mold and the upper cavity, and then pump vacuum;

Step S3: start the induction smelting device to raise the molten metal to a predetermined temperature and keep it isothermally for a period of time;

Step S4: using the hydraulic lifting platform to lift the smelting crucible to the external field action area, start the electromagnetic field to process the melt, deeply remove the gas in the melt, and maintain the uniformity of alloy composition and melt temperature;

Step S5: After the external field acts for a certain period of time, stop the electromagnetic stirring, let it stand for a period of time, and then use the constant pressure high-pressure tank to pass high-purity argon gas with a purity greater than 99.99% into the upper cavity and the lower cavity at the same time ;

Step S6: use the constant-pressure low-pressure tank to decompress the upper cavity, and use the argon pressure difference between the lower cavity and the upper cavity to pour aluminum alloy melt into the mold for casting , the casting time is 10-25s, and the pressure holding time is 5-15min; after the melt solidifies to form a casting, the pressure is relieved, and the upper cavity is opened to take out the casting.

Further, Al-Ti-B, Al-Sr or Al-RE master alloy may be used as the alloy melt modifier in step S1. Aluminum alloys such as ZL114A, ZL205A, ZL104A, ZL101, A356 and A357 can be used as aluminum alloys.

Further, in step S2, the degree of vacuum is 10-40Pa.

Further, in step S3, the isothermal standing time of the aluminum alloy melt under the vacuum condition is 18-25 min.

Further, in step S4, when the melt reaches 80-100°C above TL, the electromagnetic stirring device is started to electromagnetically stir the melt, the central magnetic induction intensity is 0-30 mT, and the electromagnetic field action time is 1-5 min.

Compared with the prior art, the present invention has the following advantages:

1. A differential pressure anti-gravity filling and solidification device and a process method under the action of an external field provided by the present invention utilize the induced current generated by the electromagnetic field to cut the molten metal during the differential pressure anti-gravity filling and solidification process, which is generated in the metal melt. Electromagnetic force promotes the forced convection of the melt, makes the solute distribution more uniform at the temperature of the melt, and strengthens nucleation and dissociation. The application of magnetic field and vacuum field during the casting process will not introduce other impurities, which is an ideal improvement. Methods of casting quality.

2. The differential pressure antigravity mold filling and solidification device and process method provided by the present invention introduce electromagnetic fields and vacuum fields during the differential pressure antigravity mold filling and solidification process, which does not affect the existing casting conditions and processes, and the equipment is simple , easy to operate, with the advantages of strong process adaptability, convenience and flexibility, low porosity of castings, and high mechanical properties, suitable for the forming and industrial production of large and medium-sized aluminum alloy castings.

3. The differential pressure anti-gravity filling and solidification device and process method provided by the present invention organically combine non-vacuum alloy smelting, metamorphism and preliminary degassing refining with vacuum field and electromagnetic field coupling deep refining to realize large-volume aluminum alloys. The deep refining of alloy melt is very beneficial for improving the compactness of large and complex aluminum alloy casting products.

Based on the above reasons, the present invention can be widely promoted in the fields of low pressure casting technology and the like.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a differential pressure antigravity filling and solidification device and a process method under the action of an external field of the present invention.

Fig. 2 is a schematic diagram of the position of the crucible during smelting, metamorphism and degassing under non-vacuum conditions of a differential pressure antigravity filling and solidification device and a process method under the action of an external field of the present invention.

3 is a schematic diagram of the position of the crucible during the deep purification of the melt under the vacuum condition of a differential pressure antigravity filling and solidification device and a process method under the action of an external field of the present invention.

In the figure: 1. Upper cavity; 2. Casting mold; 3. Aluminum alloy casting; 4. Intermediate plate; 5. Infusion tube; 6. Quartz glass observation hole; 7. Melting crucible; 8. Electromagnetic stirring device; 9. Induction smelting device; 10. Hydraulic lifting platform; 11. Position control device; 12. Lower cavity; 13. Induction electric inlet; 14. Constant pressure high pressure tank; 15. Vacuum pump; 16. Vacuum tank; 17. Gas control valve; 18. Constant pressure low pressure tank.

Detailed ways

It should be noted that the embodiments of the present invention and the features of the embodiments may be combined with each other under the condition of no conflict. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is only a part of the embodiments of the present invention, but not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the invention unless specifically stated otherwise. Meanwhile, it should be understood that, for convenience of description, the dimensions of various parts shown in the accompanying drawings are not drawn in an actual proportional relationship. Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the authorized specification. In all examples shown and discussed herein, any specific values should be construed as illustrative only and not limiting. Accordingly, other examples of exemplary embodiments may have different values. It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further discussion in subsequent figures.

In the description of the present invention, it should be understood that the orientations indicated by orientation words such as "front, rear, top, bottom, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" etc. Or the positional relationship is usually based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and these orientation words do not indicate or imply the indicated device or element unless otherwise stated. It must have a specific orientation or be constructed and operated in a specific orientation, so it should not be construed as a limitation on the scope of protection of the present invention: the orientation words "inside and outside" refer to the inside and outside relative to the contour of each component itself.

For ease of description, spatially relative terms, such as "on", "over", "on the surface", "above", etc., may be used herein to describe what is shown in the figures. The spatial positional relationship of one device or feature shown to other devices or features. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or features would then be oriented "below" or "over" the other devices or features under its device or structure". Thus, the exemplary term "above" can encompass both an orientation of "above" and "below." The device may also be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.

In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood to limit the scope of protection of the present invention.

As shown in Figures 1-3, the present invention provides a differential pressure anti-gravity filling and solidification device under the action of an external field, including: a solidification cavity, a high pressure part, a low pressure part and a vacuum part, and the solidification cavity includes: an upper cavity The upper cavity 1 and the lower cavity 12 are provided with a casting mold 2, and the upper cavity 1 and the lower cavity 12 are connected by the intermediate plate 4; the upper cavity 1 and the lower cavity An infusion pipe 5 is arranged between 12, and the infusion pipe 5 passes through the center of the intermediate plate 4; the lower end of the lower cavity 12 is provided with a hydraulic lifting platform 10, and the hydraulic lifting platform 10 passes through the position control device 11. For control, the upper end of the hydraulic lifting platform 10 is provided with a melting crucible 7; the bottom of the lower cavity 12 is provided with an induction melting device 9, and the induction melting device can be an induction heating device, such as an induction heating coil; The upper end of the smelting device 9 is provided with an electromagnetic stirring device 8 , and the material of the water cooling jacket of the electromagnetic stirring device 8 is austenitic stainless steel; the lower cavity 12 is located between the electromagnetic stirring device 8 and the induction melting device 9 . There is an induction electric inlet 13 at the corresponding position; the high-pressure part includes a constant-pressure high-pressure tank 14 and a valved air conduit, and the constant-pressure high-pressure tank 14 is connected to the upper cavity 1 and the valved air conduit through the valved air conduit. The lower end of the lower cavity 12; the low pressure part includes a constant pressure low pressure tank 18 and the valved air conduit, and the constant pressure low pressure tank 18 is connected to the upper cavity 1 through the valved air conduit; The vacuum part includes a vacuum pump 15, a vacuum tank 16, and the valved gas conduit. The vacuum pump 15 is connected to the vacuum tank 16, and the vacuum tank 16 is connected to the upper cavity 1 through the valved gas conduit. The lower end of the lower chamber 12 and the upper end of the lower chamber 12; the upper end of the lower chamber 12 is provided with a quartz glass observation hole 6; the constant pressure high pressure tank 14 is filled with high pressure argon; the constant pressure low pressure tank 18 is Low pressure argon.

Step S1: put the aluminum alloy raw material or the intermediate alloy of pure aluminum and related elements into the melting crucible 7 after drying and removing surface impurities, start the induction melting device 9 to melt the raw material into liquid, and then use the hydraulic lifting platform 10 lift the smelting crucible 7, use a metamorphic agent for metamorphism, use high-purity argon with a purity greater than 99.99% to rotate and spray for degassing, and then carry out slag removal;

Step S2: After removing the slag, use the hydraulic lifting platform 10 to lower the melting crucible 7 to the induction melting device 9, close the middle plate 4, install the infusion pipe 5, the casting mold 2 and the After the upper cavity is evacuated;

Step S3: start the induction smelting device 9 to raise the molten metal to a predetermined temperature and keep it isothermally for a period of time;

Step S4: using the hydraulic lifting platform 10 to lift the smelting crucible 7 to the external field action area, start the electromagnetic field to process the melt, deeply remove the gas in the melt, and maintain the uniformity of alloy composition and melt temperature;

Step S5: After the external field acts for a certain period of time, stop the electromagnetic stirring, let it stand for a period of time, and then use the constant pressure high-pressure tank 14 to simultaneously pass the upper cavity 1 and the lower cavity 12 into the high purity greater than 99.99%. pure argon;

Step S6: use the constant pressure low pressure tank 18 to decompress the upper cavity 1, and use the argon pressure difference between the lower cavity 12 and the upper cavity 1 to inject aluminum alloy melt into the Casting mold 2 is cast, the casting time is 10-25s, and the pressure holding time is 5-15min; after the melt solidifies to form a casting, the pressure is relieved, and the upper cavity is opened to take out the casting.

Al-Ti-B, Al-Sr or Al-RE master alloy may be used as the alloy melt modifier in step S1. The aluminum alloy can be aluminum alloys such as ZL114A, ZL205A, ZL104A, ZL101, A356 and A357; the vacuum degree in step S2 is 10-40Pa; the isothermal standing time of the aluminum alloy melt under vacuum conditions in step S3 is 18-25min; step S4 When the melt reaches 80-100°C above TL, start the electromagnetic stirring device 8 to electromagnetically stir the melt, the central magnetic induction intensity is 0-30mT, and the electromagnetic field action time is 1-5min.

Example 1

1. Put the ZL114A aluminum alloy raw material or pure aluminum and intermediate alloys such as Al-Si and Al-Mg into the smelting crucible 7 after drying and removing surface impurities, and start the induction heating device 9 to melt the raw materials to 700～710℃ liquid, and then use the hydraulic lifting platform 10 to lift the crucible to the position shown in Figure 2, use a modifier for metamorphism, and use high-purity argon with a purity greater than 99.99% to rotate and spray for degassing, and then slag removal;

2. After slag removal, use the hydraulic lifting platform 10 to lower the melting crucible 7 to the induction heating device, as shown in FIG. After type 2 and the upper cavity 1, the upper cavity 1 and the lower cavity 12 are simultaneously evacuated by 10-20 Pa using the vacuum tank 16;

3. Start the induction heating device to raise the molten metal to a predetermined temperature and keep it at an isothermal stand for 15 minutes;

4. Use the hydraulic lifting platform 10 to lift the smelting crucible 7 to the electromagnetic stirring device 8 in the external field action area, start the electromagnetic stirring device 8 to process the melt for 1 min, and deeply remove the gas in the melt, Maintain uniformity of alloy composition and melt temperature;

5. After the external field acts for a certain period of time, stop the electromagnetic stirring, let it stand for 10s, and then use the constant pressure high-pressure tank 14 to pass the upper chamber 1 and the lower chamber 12 into high-purity argon with a purity greater than 99.99% at the same time. gas;

6. Use the constant pressure and low pressure tank 18 to decompress the upper cavity 1, and use the argon pressure difference between the lower cavity 12 and the upper cavity 1 to press the aluminum alloy melt into the casting Type 2 is cast, the casting time is 10-25s, and the pressure holding time is 5-15min; after the melt solidifies to form a casting, the pressure is relieved, and the upper cavity is opened to take out the casting.

In this embodiment, the alternating rotating magnetic field is used to promote forced convection of the ZL114A aluminum alloy melt, which uniformizes the melt temperature field, strengthens the nucleation and dissociation of the crystal nucleus, realizes the grain refinement of the casting structure, and reduces the inclusions. The deep purification of ZL114A aluminum alloy melt was realized by using vacuum field and electromagnetic long coupling effect, and the casting performance was improved.

Example 2

1. Put ZL205A aluminum alloy raw materials or intermediate alloys such as pure aluminum and Al-Cu into the melting crucible 7 after drying and removing surface impurities, start the induction melting device 9 to melt the raw materials into 700-715 ℃ liquid, and then use The hydraulic lifting platform 10 lifts the smelting crucible 7 to the position shown in FIG. 2 , uses a metamorphic agent for metamorphism, uses a high-purity argon gas with a purity greater than 99.99% to rotate and blow for degassing, and then performs slag removal;

2. After slag removal, use the hydraulic lifting platform 10 to lower the melting crucible 7 to the induction melting device 9, close the middle plate 4, install the infusion pipe 5, the casting mold 2 and the After the upper cavity 1, the upper cavity 1 and the lower cavity 12 are simultaneously evacuated by 10-30 Pa using the vacuum tank 16;

3. Start the induction smelting device 9 to raise the molten metal to a predetermined temperature and keep it at rest for 18 minutes at an isothermal temperature;

4. Use the hydraulic lifting platform 10 to lift the smelting crucible 7 to the electromagnetic stirring device 8 in the external field action area, start the electromagnetic stirring device 8 to process the melt for 2 minutes, and deeply remove the gas in the melt, Maintain uniformity of alloy composition and melt temperature;

5. After the external field acts for a certain period of time, stop the electromagnetic stirring, let it stand for 20s, and then use the constant pressure high-pressure tank 14 to pass the upper chamber 1 and the lower chamber 12 into the high-purity argon with a purity greater than 99.99% at the same time. gas;

Example 3

1. Put ZL104A or A357 aluminum alloy raw materials or pure aluminum and intermediate alloys such as Al-Si and Al-Mg into the melting crucible 7 after drying and removing surface impurities, and start the induction melting device 9 to melt the raw materials into 710~ 720 ° C liquid, and then use the hydraulic lifting platform 10 to lift the melting crucible 7 to the position shown in Figure 2, use a modifier for metamorphism, and use high-purity argon with a purity greater than 99.99%. , and then carry out slag removal;

2. After slag removal, use the hydraulic lifting platform 10 to lower the melting crucible 7 to the induction heating device, as shown in FIG. After type 2 and the upper cavity 1, the upper cavity 1 and the lower cavity 12 are simultaneously evacuated by 20-40 Pa using the vacuum tank 16;

3. Start the induction smelting device 9 to raise the molten metal to a predetermined temperature and keep it at rest for 22 minutes at an isothermal temperature;

4. Use the hydraulic lifting platform 10 to lift the smelting crucible 7 to the electromagnetic stirring device 8 in the external field action area, start the electromagnetic stirring device 8 to process the melt for 3 minutes, and deeply remove the gas in the melt, Maintain uniformity of alloy composition and melt temperature;

5. After the external field acts for a certain period of time, stop the electromagnetic stirring, let it stand for 25s, and then use the constant pressure high-pressure tank 14 to pass the upper chamber 1 and the lower chamber 12 into high-purity argon with a purity greater than 99.99% at the same time. gas;

In this embodiment, the alternating rotating magnetic field is used to promote forced convection of the ZL104A and A357 aluminum alloy melts, which uniformizes the melt temperature field, strengthens the nucleation and dissociation of the crystal nucleus, realizes the grain refinement of the casting structure, and reduces the inclusions. The deep purification of ZL104A aluminum alloy melt was realized by using the vacuum field and electromagnetic long coupling effect, and the performance of the casting was improved.

Example 4

1. Put ZL101 or A356 aluminum alloy raw materials or pure aluminum and intermediate alloys such as Al-Si and Al-Mg into the melting crucible 7 after drying and removing surface impurities, and start the induction heating coil 9 to melt the raw materials into 710~ 715 ° C liquid, then use the hydraulic lifting platform 10 to lift the crucible to the position shown in Figure 2, use a modifier for metamorphism, and use high-purity argon with a purity greater than 99.99% to rotate and spray to degas, and then degas slag;

2. After removing the slag, use the hydraulic lifting platform 10 to lower the melting crucible 7 to the induction melting device 9, as shown in FIG. 3 . Close the middle plate 4, install the infusion tube 5, the mold 2 and the upper cavity 1, and use the vacuum tank 16 to vacuum the upper cavity 1 and the lower cavity 12 at the same time 15-30Pa;

3. Start the induction heating coil to raise the molten metal to the predetermined temperature and keep it at an isothermal temperature for 25 minutes;

4. Use the hydraulic lifting platform 10 to lift the smelting crucible 7 to the electromagnetic stirring device 8 in the external field action area, start the electromagnetic stirring device 8 to process the melt for 5 minutes, and deeply remove the gas in the melt, Maintain uniformity of alloy composition and melt temperature;

5. After the external field acts for a certain period of time, stop the electromagnetic stirring, let it stand for 30s, and then use the constant pressure high-pressure tank 14 to pass the upper chamber 1 and the lower chamber 12 into high-purity argon with a purity greater than 99.99% at the same time. gas;

6. Use the constant pressure and low pressure tank 18 to depressurize the upper cavity 1, and use the lower cavity 12 and the casting mold 2 for casting, the casting time is 10-25s, and the pressure holding time is 5-15min; After the melt solidifies to form a casting, the pressure is relieved, and the upper cavity is opened to take out the casting.

In this embodiment, the alternating rotating magnetic field is used to promote forced convection of the ZL101 and A356 aluminum alloy melts, which uniformizes the melt temperature field, strengthens the nucleation and dissociation of the crystal nucleus, realizes the grain refinement of the casting structure, and reduces the inclusions. The deep purification of ZL101 and A356 aluminum alloy melts was realized by using the vacuum field and electromagnetic long-coupling, and the performance of the castings was improved.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims

A differential pressure anti-gravity filling and solidification device under the action of an external field is characterized in that it comprises: a solidification cavity, a high pressure part, a low pressure part and a vacuum part, the solidification cavity comprises: an upper cavity and a lower cavity, the The upper cavity is provided with a casting mold, the upper cavity and the lower cavity are connected by an intermediate plate, and an infusion tube is arranged between the upper cavity and the lower cavity, and the infusion tube passes through the intermediate plate The lower end of the lower cavity is provided with a hydraulic lifting platform, the upper end of the hydraulic lifting platform is provided with a melting crucible, the bottom of the lower cavity is provided with an induction melting device, and the upper end of the induction melting device is provided with an electromagnetic a stirring device, the lower cavity is provided with an induction electric inlet at the corresponding position of the electromagnetic stirring device and the induction melting device; the high pressure part includes a constant pressure high pressure tank and a valved air duct, the constant pressure high pressure tank The lower ends of the upper cavity and the lower cavity are connected through the valved air conduit; the low pressure part includes a constant pressure low pressure tank and the valved air conduit, and the constant pressure low pressure tank passes through the belt The valve air conduit is connected to the upper cavity; the vacuum part includes a vacuum pump, a vacuum tank and the valved air conduit, the vacuum pump is connected to the vacuum tank, and the vacuum tank passes through the valved air conduit connected to the lower end of the upper cavity and the upper end of the lower cavity.
A differential pressure anti-gravity filling and solidification device under the action of an external field according to claim 1, wherein the material of the water cooling jacket of the electromagnetic stirring device is austenitic stainless steel; the upper end of the lower cavity is provided with Quartz glass viewing port.
A differential pressure anti-gravity filling and solidification device under the action of an external field according to claim 1, wherein the constant pressure high pressure tank contains high pressure argon gas; the constant pressure low pressure tank contains low pressure argon gas.
A solidification process of a differential pressure anti-gravity filling solidification device under the action of an external field as described in any of claims 1-3, wherein the solidification process step comprises:

Step S1: put the aluminum alloy raw material or the intermediate alloy of pure aluminum and related elements into the smelting crucible after drying and removing surface impurities, start the induction melting device to melt the raw material into liquid, and then use the hydraulic lifting platform to melt the raw material into a liquid. The smelting crucible is lifted up, metamorphic agent is used for metamorphism, and high-purity argon gas with a purity greater than 99.99% is used for degassing, and then slag removal is carried out;

Step S2: After slag removal, use the hydraulic lifting platform to lower the melting crucible to the induction melting device, close the middle plate, install the infusion pipe, the mold and the upper cavity, and then pump vacuum;

Step S3: start the induction smelting device to raise the molten metal to a predetermined temperature and keep it isothermally for a period of time;

Step S4: using the hydraulic lifting platform to lift the smelting crucible to the external field action area, start the electromagnetic field to process the melt, deeply remove the gas in the melt, and maintain the uniformity of alloy composition and melt temperature;

Step S5: After the external field acts for a certain period of time, stop the electromagnetic stirring, let it stand for a period of time, and then use the constant pressure high-pressure tank to pass high-purity argon gas with a purity greater than 99.99% into the upper cavity and the lower cavity at the same time ;

Step S6: use the constant-pressure low-pressure tank to decompress the upper cavity, and use the argon pressure difference between the lower cavity and the upper cavity to pour aluminum alloy melt into the mold for casting , the casting time is 10-25s, and the pressure holding time is 5-15min; after the melt solidifies to form a casting, the pressure is relieved, and the upper cavity is opened to take out the casting.
The solidification process of a differential pressure anti-gravity filling solidification device under the action of an external field according to claim 4, characterized in that in step S1, the alloy melt modifier can be Al-Ti-B, Al-Sr or Al- RE master alloy. Aluminum alloys such as ZL114A, ZL205A, ZL104A, ZL101, A356 and A357 can be used.
The solidification process of a differential pressure anti-gravity filling solidification device under the action of an external field according to claim 4, wherein the degree of vacuum in step S2 is 10-40 Pa.
The solidification process of a differential pressure antigravity filling and solidification device under the action of an external field according to claim 4, wherein the isothermal standing time of the aluminum alloy melt under the vacuum condition in step S3 is 18-25min.
The solidification process of a differential pressure anti-gravity filling and solidifying device under the action of an external field according to claim 4, wherein in step S4, when the melt reaches 80-100°C above TL, an electromagnetic stirring device is started to electromagnetically conduct the melt on the melt. Stir, the central magnetic induction intensity is 0 ~ 30mT, and the electromagnetic field action time is 1 ~ 5min.